N-ACETYLASPARTATE AS AN IN-VIVO MARKER OF NEURONAL VIABILITY IN KAINATE-INDUCED STATUS EPILEPTICUS - H-1 MAGNETIC-RESONANCE SPECTROSCOPIC IMAGING

N-acetylaspartate (NAA) has been proposed as a marker of neuronal dens ity. Therefore, regional measurement of NAA by magnetic resonance spec troscopic imaging (MRSI) may provide a sensitive method for detection of selective neuronal loss, in contrast to conventional imaging techni ques such as magnetic resonance imaging (MRI). To test this hypothesis , we produced selective neuronal injury by kainate-induced status epil epticus. Three days later three-dimensional H-1-MRSI was obtained and compared with conventional T-2-weighted MRI and histological findings in normal and kainate-treated rats. Reduction of NAA determined by MRS I in piriform cortex, amygdala, and hippocampus correlated well with n euronal injury determined from histology. Changes of NAA, without any MRI changes in hippocampus, indicated greater sensitivity of MRSI for detection of neuronal injury. These results are consistent with the hy pothesis that reduction of NAA measured by MRSI may be a sensitive mar ker of neuronal injury in vivo in a variety of disease states.